OT:

I had my rollaboard weighed when I flew BR. An agent standing by the jetway simply picked up each person's bag and determined right there whether it was overweight or not (mine was ). I think the limit was 10kg, but I could be wrong about that.

Another time flying SQ, I packed about 30 freshly printed books into my rollaboard. It must have weighed 50 lbs. The FA even offered to help me put that monster in the overhead bin.